Bioactive ZnO-assisted 1393 glass scaffold promotes osteogenic differentiation: Some studies.

We developed ZnO-assisted 1393 bioactive glass-based scaffold with suitable mechanical properties through foam replica technique and observed to be suitable for bone tissue engineering application. However, the developed scaffolds' ability to facilitate cellular infiltration and integration was further assessed through in vivo studies in suitable animal model. Herein, the pure 1393 bioactive glass (BG) and ZnO-assisted 1393 bioactive glass- (ZnBGs; 1, 2, 4 mol% ZnO substitution for SiO2 in pure BG is named as Z1BG, Z2BG, Z3BG, respectively) based scaffolds were prepared through sol-gel route, followed by foam replica techniques and characterized by a series of in vitro and some in vivo tests. Different cell lines like normal mouse embryonic cells (NIH/3T3), mouse bone marrow stromal cells (mBMSc), peripheral blood mononuclear cells, that is, lymphocytes and monocytes (PBMC) and U2OS (carcinogenic human osteosarcoma cells) were used in determination and comparative analysis of the biological compatibility of the BG and ZnBGs. Also, the alkaline phosphatase (ALP) activity, and osteogenic gene expression by primer-specific osteopontin (OPN), osteocalcin (OCN), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were performed to study osteogenic differentiability of the stromal cells in different BGs. Moreover, radiological and histopathological tests were performed in bone defect model of Wister rats to evaluate the in vivo bone regeneration and healing. Interestingly, these studies demonstrate augmented biological compatibility, and superior osteogenic differentiation in ZnBGs, in particular Z3BG than the pure BG in most cases.

Synthesis, Characterization, and Ionic Conductivity Studies of Simultaneously Substituted K- and Ga-Doped BaZrO3.

Ceramic fuel cells possess tremendous advantages over PMFCs due to their fuel flexibility and requirement of low-purity hydrogen. Despite high conversion efficiency, the high cost of ultra high-purity hydrogen required for the operation limits the application of PMFCs. Although ceramic fuel cells operate at elevated temperature, high performance coupled with multifuel flexibility makes ceramic fuel cells a superior option as a static power source to generate electricity compared to thermal coal-fired power plants. BaZr1-x Y x O3-x/2 based protonic conductors get a high degree of interest due to their superior structural stability, but their poor conductivity at higher temperature limits the performance of ceramic fuel cells. To overcome the low ionic conductivity issues of BaZrO3 based materials at elevated temperature, the simultaneous doping of smaller Ga on the Zr site and K on the Ba site was employed here to create higher concentration of oxide-ion vacancies for the realization of superior conductivities. The simultaneous substitution of K and Ga created the oxygen vacancy-type point defects resulting in higher ionic conductivity ∼10-2 S/cm above 650 °C. The conductivity represented here for the Ba0.8K0.2Zr0.8Ga0.2O2.8 sample is superior or equivalent to the conductivity obtained for yttria-stabilized zirconia, a well-known ceramic oxide-ion electrolyte.

CuO assisted borate 1393B3 glass scaffold with enhanced mechanical performance and cytocompatibility: An In vitro study.

Herein, three dimensional porous 1393B3 borate-based glass (BBG) scaffold along with their CuO derivatives (C1BBG, C2BBG, and C3BBG) tailored with trabecular bones' architecture were prepared by melt-quench route followed by foam replica technique. The properties of 'CuO incorporated' scaffolds, as compared to 'as prepared' scaffold were analyzed by a series of In vitro investigations for enhancement in biological compatibility, bioactivity, and physicomechanical performances. The in vitro study demonstrates superior mechanochemical stability of CBBGs (CuO derived 1393B3) than the pure BBG, while causing no or minimal effect on bioactivity and cytocompatibility post CuO incorporation to the BBG. In fact, the biological compatibility examined through MTT, Live/Dead, and cell adhesion study using the L929 cell lines was enhanced in the CBBGs up to 1% CuO incorporated scaffolds (C1BBG and C2BBG) in most cases. However, the enhanced biological compatibility was observed in C1BBG in comparison to other BBGs. Thus, the CuO incorporation into BBG enhanced mechanochemical and biological performance without affecting the bioactivity of the scaffold; henceforth, CBBGs could be considered neo bone tissue regenerative biomaterials.

Design and development of a multipurpose portable heating setup for 45S5 bioglass and other ceramic samples.

As per the voices in the precision manufacturing industries, the machining of brittle materials such as glass and diamond is intricate owing to their thermo-mechanical properties. Machining of the brittle material with a localized heating method produced softness in the work material during the operation, resulting in microcracks and voids on the finished surface due to thermal stresses. Such pressing issues are solved by dry machining with bulk heating. The objective of the present research is to develop a sophisticated lab-made portable multipurpose heating setup for enabling various potent applications such as machining, elevated temperature scratch and indentation tests, and grinding, among other things, on hard and brittle materials. The mentioned process is done by softening the material with preheating of the samples. The overall dimensions of the developed setup are 105 × 150 × 53 mm3. This setup has been evaluated at different temperatures of the 45S5 bioglass sample surface up to 426 °C and is capable of holding and heating the samples.

Studies on effect of CuO addition on mechanical properties and in vitro cytocompatibility in 1393 bioactive glass scaffold.

Copper doped bioactive glasses have been reported as the potential biomaterial for diseased or damaged bone repair and act as stimulants to new bones formation. In the present manuscript, we have synthesized 1393 derived glass based scaffold with the general formula of (54.6 - X)SiO2·6Na2O·7.9 K2O·7.7 MgO·22 CaO·1.74 P2O5·XCuO (all are in mole%; where X = 0,1,2,3) through traditional melt-quench route and the samples were designated as 1393, 1393-1Cu, 1393-2Cu and 1393-3Cu respectively. Polymer foam with interconnected pores has been used on later stage to prepare porous (porosity > 50%) bioactive scaffolds. The addition of CuO in glass scaffolds was to ensure its cytocompatibility, ability to enhance cell proliferation and improvements in mechanical properties. Increasing trend of CuO in the 1393 glass scaffold has resulted in increasing compressive and flexural strength and elastic modulus of the scaffolds. In-vitro cellular growth inhibition and cell viability assay of CuO incorporated 1393 glass scaffolds demonstrated that it did not inhibit proliferation and viability of human squamous carcinoma cell (SCC-25) at low materials concentration. The materials caused moderate level of apoptosis at higher concentrations and were also tolerated by human RBC as studied by hemolytic assay. The results indicated that CuO incorporated 1393 scaffolds could be a potential biomaterial for neobone tissue engineering application.

Enhanced bioactivity, biocompatibility and mechanical behavior of strontium substituted bioactive glasses.

Strontium contained biomaterials have been reported as a potential bioactive material for bone regeneration, as it reduces bone resorption and stimulates bone formation. In the present investigation, the bioactive glasses were designed to partially substitute SrO for SiO2 in Na2O-CaO-SrO-P2O5-SiO2 system. This work demonstrates that the substitution of SrO for SiO2 has got significant benefit than substitution for CaO in the bioactive glass. Bioactivity was assessed by the immersion of the samples in simulated body fluid for different intervals. The formation of hydroxy carbonate apatite layer was identified by X-ray diffractometry, scanning electron microscopy (SEM) and energy dispersive spectroscopy. The elastic modulus of the bioactive glasses was measured and found to increase with increasing SrO for SiO2. The blood compatibility of the samples was evaluated. In vitro cell culture studies of the samples were performed using human osteosarcoma U2-OS cell lines and found a significant improvement in cell viability and proliferation. The investigation showed enhancement in bioactivity, mechanical and biological properties of the strontia substituted for silica in glasses. Thus, these bioactive glasses would be highly potential for bone regeneration.

Influence of barium substitution on bioactivity, thermal and physico-mechanical properties of bioactive glass.

Barium with low concentration in the glasses acts as a muscle stimulant and is found in human teeth. We have made a primary study by substituting barium in the bioactive glass. The chemical composition containing (46.1-X) SiO2--24.3 Na2O-26.9 CaO-2.6 P2O5, where X=0, 0.4, 0.8, 1.2 and 1.6mol% of BaO was chosen and melted in an electric furnace at 1400±5°C. The glasses were characterized to determine their use in biomedical applications. The nucleation and crystallization regimes were determined by DTA and the controlled crystallization was carried out by suitable heat treatment. The crystalline phase formed was identified by using XRD technique. Bioactivity of these glasses was assessed by immersion in simulated body fluid (SBF) for various time periods. The formation of hydroxy carbonate apatite (HCA) layer was identified by FTIR spectrometry, scanning electron microscope (SEM) and XRD which showed the presence of HCA as the main phase in all tested bioactive glass samples. Flexural strength and densities of bioactive glasses have been measured and found to increase with increasing the barium content. The human blood compatibility of the samples was evaluated and found to be pertinent.